%link
\begin{verbatim}
sage: (r,s) = (7,5)
sage: G = SymmetricGroup(r*s)
sage: S = [ i+s*j for i in range(1,s+1) for j in range(r) ]
sage: G(S) 
(2,6,26,24,14,32,20,28,34,30,10,12,22,4,16,8)
  (3,11,17,13,27,29,5,21,33,25,19,23,9,7,31,15)
\end{verbatim}
